In our previous grant we began to test CMV vaccine in renal transplant patients. The complementary goals of this research were to see if vaccination would protect the CMV-seronegative prospective recipients from disease and rejection and to see if the vaccine virus would become latent and be reactivated under conditions of immunosuppression. As described in our previous application, the first year consisted of an open trial, during which we gathered preliminary evidence for safety. Efficacy was not established, however, and is now the subject of a controlled trial that has begun during the second year of the original grant and is expected to continue.